The present invention relates generally to conveying systems and, more particularly, to a conveyor system that changes the orientation of a product or array of products as they are being conveyed.
For many material handling systems, a product, or array of products, it is desirable to change the orientation of the product before it is fed to a downstream stage of the material handling system, such as a wrapper, case packer, bundler, palletizer, or other product “warehouser”. For instance, for many paper roll handling systems, the paper rolls are conventionally conveyed on their side (lay-flat orientation) but are packaged in an upright position. To change the orientation of the paper rolls, the paper roll handling system will include an upending stage that is designed to upend the paper rolls.
Conventional upending handling systems have taken many forms as designers made efforts to improve throughput as well as consistency in changing the orientation of the products.
Early efforts at designing upending handling systems involved the use of twisted guide rails or gravity drops from one handling stage (“conveyor”) to another. These early systems were found to be unreliable and typically had one set of rails for each product to be handled. As a result, component changes were required each time a new type or size of product was to be conveyed.
A second type of upending device incorporated a powered conveyor with a side mounted belt conveyor. The belt conveyor was height, speed, and angle adjustable and it required adjusting the side belt for each product that ran through it but was much more flexible than previous designs and could be adjusted to run several different products. It could, with the correct guide rail adjustment, allow products to pass through without being upended. One of the drawbacks of this type of upending device was that it was very difficult to carry out fine tune adjustments and could require several adjustment setting changes during a run dependant on package density (e.g., firmness of the roll wind) or conveying surface (e.g., poly) changes that effect the slip of the conveying surface on the chain/belt arrangements or could even require adjustments based on either looseness of the conveyed product or the dust build up on the equipment during a shift run. This type of upending device would typically be built with either a clockwise or counterclockwise rotation and could even be supplied with two belts to allow upending in either direction. However, such systems did not allow product to back up on the upending belt without risking damage to the product.
A third type of upending device also incorporated a powered conveyor with a side mounted belt conveyor. This design however allowed the belt to be switched from either the left or right side of the device to allow packages passing through to be upended either clockwise or counterclockwise with the use of only one belt. This design was less costly and more customer friendly as there was no equipment off the side of the conveyor when not in use and it allowed the customer to change package orientations at a later date without adding more equipment. However, this design still required that the belt conveyor height, speed and angle be adjustable and it required adjusting the side belt for each product that ran through it but was much more flexible and could be adjusted to run several different products. It could also with the correct guide rail adjustment allow packages to pass through without being upended. This was still a very difficult fine tune adjustment and could require several adjustment setting changes during a run dependant on package density (firmness of the roll wind) or conveying surface changes that effect the slip of the conveying surface on the chain/belt arrangement or could even require adjustments based on either looseness of the conveyed product or the dust build up on the equipment during a run. Similar to previous designs, this design was susceptible to product damage if product was allowed to back up on the upending belt.
Another type of upending device incorporated a side gripper elevator that would pick up product from the side and as it traveled through the gripper. The side in which the product was handled would be changed and upend the product during the elevation change. This style of gripper upender was very positive and allowed for an easy hand crank adjustment between products. This device required that product change elevation during the upending process. Another drawback of this type of device was that it could not be switched between an upending device and a non-upending device. As a result, a bypass system had to be added that allowed the upending device to be bypassed when upending of a device was not desired.
Another type of upending device was developed by Pack Air Inc. of Neenah, Wis. and it used two conveying surfaces to effectively “twist” the product as the product was being conveyed from an infeed end to a discharge end. The helical upending device would positively upend the product and would not require any operator changes when either product sizes changed or when density or conveyor surface changes were made. These devices were very positive and did not require speed or rail adjustments to run different products. However, a drawback of this early helical upender was that the conveying surfaces were quite long, and it required spring take ups for the chain. Moreover, a bypass line was required if products did not require upending.
In effort to address the drawbacks of these early helical upenders, Pack Air Inc. then developed a much shorter helical upending device. For example, this second generation of the helical upending device was approximate ten feet or half the length of the early helical upender. This helical upending device also incorporated an air take up device. The upender could be setup for either clockwise or counterclockwise rotation but not both. While this helical upending device provided very positive conveyance and also did not require adjustments between product changes, the device was limited to fixed side upending and required a bypass to allow product that did not require orientation changes or the product would have to be reoriented after being discharged.
A number of design efforts have been made to effectively and efficiently provide bypass of the helical upender for those products that do not require reorientation. Such efforts have included diverting the products off line and going around the device, putting the device on slides and interchanging the device with a conveyor that provides pass-through, or reorienting the product after it passes through the device. While generally effective in providing product bypass, these bypassing systems enlarge the footprint of the material handling system as well as increase system acquisition and maintenance costs.